[Firebird-devel] [FB-Tracker] Created: (CORE-2053) Computed expressions may be optimized badly if used inside the RETURNING clause of the INSERT statement

[Dmitry Y. (JIRA) <tr...@fi...>]

Computed expressions may be optimized badly if used inside the RETURNING clause of the INSERT statement
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                 Key: CORE-2053
                 URL: http://tracker.firebirdsql.org/browse/CORE-2053
             Project: Firebird Core
          Issue Type: Bug
          Components: Engine
    Affects Versions: 2.1.1, 2.5 Alpha 1, 2.1.0
            Reporter: Dmitry Yemanov


Test case:

create table t1 (col1 int);
create index i1 on t1 (col1);
commit;
insert into t1 (col1) values (1);
commit;
create table t2 (col2 int);
commit;

select case when exists (select 1 from t1 where col1 = col2) then 1 else 0 end from t2;
-- PLAN (T1 INDEX (I1))
-- PLAN (T2 NATURAL)
-- Everything is okay, T1 is accessed via an index

insert into t2 (col2) values (1) returning case when exists (select 1 from t1 where col1 = col2) then 1 else 0 end;
-- PLAN (T1 NATURAL)
-- Full scan is chosen, this is a bug


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